An Essay Concerning Human Understanding
By
John Locke
Book II:
Of Ideas, Chapters 12-33

Having treated of SIMPLE MODES in the foregoing chapters, and given several instances of some of the most considerable of them, to show what they are, and how we come by them; we are now in the next place to consider those we call MIXED MODES; such are the complex ideas we mark by the names OBLIGATION, DRUNKENNESS, a LIE, &c.; which consisting of several combinations of simple ideas of DIFFERENT kinds, I have called mixed modes, to distinguish them from the more simple modes, which consist only of simple ideas of the SAME kind. These mixed modes, being also such combinations of simple ideas as are not looked upon to be characteristical marks of any real beings that have a steady existence, but scattered and independent ideas put together by the mind, are thereby distinguished from the complex ideas of substances.

2. Made by the Mind.

That the mind, in respect of its simple ideas, is wholly passive, and receives them all from the existence and operations of things, such as sensation or reflection offers them, without being able to MAKE any one idea, experience shows us. But if we attentively consider these ideas I call mixed modes, we are now speaking of, we shall find their origin quite different. The mind often exercises an ACTIVE power in making these several combinations. For, it being once furnished with simple ideas, it can put them together in several compositions, and so make variety of complex ideas, without examining whether they exist so together in nature. And hence I think it is that these ideas are called NOTIONS: as they had their original, and constant existence, more in the thoughts of men, than in the reality of things; and to form such ideas, it sufficed that the mind put the parts of them together, and that they were consistent in the understanding without considering whether they had any real being: though I do not deny but several of them might be taken from observation, and the existence of several simple ideas so combined, as they are put together in the understanding. For the man who first framed the idea of HYPOCRISY, might have either taken it at first from the observation of one who made show of good qualities which he had not; or else have framed that idea in his mind without having any such pattern to fashion it by. For it is evident that, in the beginning of languages and societies of men, several of those complex ideas, which were consequent to the constitutions established amongst them, must needs have been in the minds of men before they existed anywhere else; and that many names that stood for such complex ideas were in use, and so those ideas framed, before the combinations they stood for ever existed.

3. Sometimes got by the Explication of their Names.

Indeed, now that languages are made, and abound with words standing for such combinations, an usual way of GETTING these complex ideas is, by the explication of those terms that stand for them. For, consisting of a company of simple ideas combined, they may, by words standing for those simple ideas, be represented to the mind of one who understands those words, though that complex combination of simple ideas were never offered to his mind by the real existence of things. Thus a man may come to have the idea of SACRILEGE or MURDER, by enumerating to him the simple ideas which these words stand for; without ever seeing either of them committed.

4. The Name ties the Parts of mixed Modes into one Idea.

Every mixed mode consisting of many distinct simple ideas, it seems reasonable to inquire, Whence it has its unity; and how such a precise multitude comes to make but one idea; since that combination does not always exist together in nature? To which I answer, it is plain it has its unity from an act of the mind, combining those several simple ideas together, and considering them as one complex one, consisting of those parts; and the mark of this union, or that which is looked on generally to complete it, is one NAME given to that combination. For it is by their names that men commonly regulate their account of their distinct species of mixed modes, seldom allowing or considering any number of simple ideas to make one complex one, but such collections as there be names for. Thus, though the killing of an old man be as fit in nature to be united into one complex idea, as the killing a man's father; yet, there being no name standing precisely for the one, as there is the name of PARRICIDE to mark the other, it is not taken for a particular complex idea, nor a distinct species of actions from that of killing a young man, or any other man.

5. The Cause of making mixed Modes.

If we should inquire a little further, to see what it is that occasions men to make several combinations of simple ideas into distinct, and, as it were, settled modes, and neglect others, which in the nature of things themselves, have as much an aptness to be combined and make distinct ideas, we shall find the reason of it to be the end of language; which being to mark, or communicate men's thoughts to one another with all the dispatch that may be, they usually make SUCH collections of ideas into complex modes, and affix names to them, as they have frequent use of in their way of living and conversation, leaving others which they have but seldom an occasion to mention, loose and without names that tie them together: they rather choosing to enumerate (when they have need) such ideas as make them up, by the particular names that stand for them, than to trouble their memories by multiplying of complex ideas with names to them, which they seldom or never have any occasion to make use of.